2,116 officers were assaulted with a firearm, but only 6.1% of those 2,116 were injured in the assault. That's approximately 129 firearm injuries. That means the rate of non-fatal firearm injuries is approximately 16.1 per 100,000. In 2012 the rate of non-fatal firearm injuries from assault was approximately 15.67 per 100,000 for the general population. When adjusted for the sex demographics of the police (88% male) the rate is 24.93 per 100,000.

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4700838/#!po=19...

Edit: It looks like the non-fatal firearm injury rate for officers is actually 23.6 per 100k. I had the wrong number in the denominator because not all police stations responded to the FBI survey.